Production and characterization of environmentally friendly lead free piezoelectric particle added PVDF composites for piezoelectric applications

Today, the increasing demand for energy continues to diversify and grow with new technological advancements and various application areas. Scientific research focused on developing high-performance and innovative materials to meet small, medium, and large-scale energy requirements has also gained momentum. This study focuses on piezoelectric materials, particularly as small-scale energy sources, to address the energy needs of miniature systems, which are among the most innovative products in the microelectronics industry. Piezoelectric materials, with their ability to convert mechanical energy into electrical energy and vice versa, have garnered significant interest across numerous sectors such as automotive, healthcare, and more, for applications like sensors, actuators, and transducers. In today's world, where eco-friendly and renewable energy production has gained great importance, piezoelectric materials provide ideal solutions in various fields. This has accelerated the pace of research into piezoelectric materials, which has been ongoing for more than half a century. Moreover, advancements in nanomaterials and characterization techniques offer researchers opportunities to develop innovative approaches. In recent years, with the rise of environmental awareness, research into developing alternative materials with similar superior properties to lead (Pb)-based piezoelectric compositions has yielded significant outcomes. In this context, the present study aims to develop lightweight, flexible, and high-performance composites by producing boron (B³⁺)-doped BNT-6BT piezoceramic powders, which offer a structure and properties comparable to commonly used lead-based PZT ceramics, and incorporating these powders into a PVDF polymer matrix. The piezoceramic powders synthesized via the hydrothermal method were characterized using XRD and SEM-EDX analyses. These powders were added to PVDF polymer as an additive, and fiber structures were produced using the electrospinning method. The morphology of the fibers, which form the main component of the composite structure, was examined using SEM-EDX techniques, while the changes in the β-phase responsible for piezoelectric properties were analyzed in detail by FTIR analyses. In terms of structure-property-performance evaluation, the electrical properties of PVDF (polyvinylidene fluoride) fiber composite samples produced with and/or without BNT-BT piezo ceramic particle additives using the electrospinning method were characterized through capacitance and dielectric loss (tan δ) in the frequency range of 1 Hz to 1 MHz (1–1,000,000 Hz) and piezoelectric response measurements at room temperature. Thanks to these multifaceted electrical characterizations, evaluations have been made regarding the potential application areas of boron-containing and non-containing BNT-BT based perovskite crystal structured piezoceramic doped and/or undoped PVDF polymer fiber composite materials in sensors, energy storage, and dielectric components. The findings obtained indicate that the incorporation of boron-doped piezoceramic powders into the PVDF polymer results in significant improvements in dielectric and piezoelectric performance, in line with the increase in the polar β phase of the fiber composite structures. These results reveal the significant contribution potential of PVDF polymer-based flexible and lightweight fiber composites for energy harvesting in wearable electronics.